CAREER: Optical Single Atom Detection for Nuclear Astrophysics

该奖项支持一种光学显微镜的开发、建造和调试，该显微镜能够对冰冻氖薄膜内捕获的单个原子进行成像。最初，这台单原子显微镜将捕捉并计算在氖原子和氦原子碰撞中产生的镁原子的数量。对这些罕见碰撞的详细测量将有助于解释铜、银和其他重化学元素的起源和丰度。由于单原子显微镜将使这类测量的灵敏度提高至少一百倍，因此模拟这些元素产生的恒星内部条件的实验室实验将首次成为可能。与此同时，PI将开发一个模块化天文馆项目，描述恒星内部的化学元素是如何形成的。这些模块将在国家超导回旋加速器实验室的虚拟之旅的背景下呈现，强调在实验室进行的研究如何影响我们对这一过程的理解，以及这项研究如何有益于社会。该项目的主要研究目标是研制和委托一台单原子显微镜，用于测量与核天体物理学相关的罕见核反应。反冲产物将在惰性气体固体中被捕获，然后使用共振激光激发和单光子探测器进行光学检测。为镁设计的单原子显微镜，如果加上反冲分离器，就可以测量氖-氦核聚变反应，灵敏度至少提高一百倍。这些反应在中子的产生中起着关键作用，而中子的产生推动了大质量恒星内部的慢中子捕获过程（s过程），这一过程负责产生大约一半的质量在60到90之间的重元素，包括铜和银。该项目的步骤包括演示固体氖中镱的光学单原子探测，校准该技术的效率、灵敏度和选择性，最后建造并调试一台单原子显微镜，用于测量产生镁原子的核反应。关键步骤包括详细了解各种光学元件中杂质产生的光学背景，固体惰性气体中钇和镁的光学光谱，以及高光收集效率衍射限制光学成像系统的设计。

This award supports the development, construction, and commissioning of an optical microscope capable of imaging individual atoms that are captured inside a thin film of frozen neon. Initially, this single atom microscope will capture and count the number of magnesium atoms produced in collisions of neon and helium atoms. Detailed measurements of these rare collisions will help explain the origin and abundance of copper, silver, and other heavy chemical elements. Because the single atom microscope will increase the sensitivity of these types of measurements by at least a factor of one hundred, laboratory experiments that mimic the conditions inside of stars where these elements are produced will be possible for the first time. In parallel, the PI will develop a modular planetarium program that describes how the chemical elements are formed inside of stars. These modules will be presented within the context of a virtual tour of the National Superconducting Cyclotron Laboratory, which emphasizes how research being conducted at the Lab impacts our understanding of this process and how this research is beneficial to society.The primary research goal of this project is to develop and commission a single atom microscope for measuring rare nuclear reactions that are relevant for nuclear astrophysics. The recoil products will be captured within the noble gas solid and then optically detected using resonant laser excitation and single photon detectors. A single atom microscope designed for magnesium, when coupled with a recoil separator, would allow for measurements of neon-helium nuclear fusion reactions with at least a hundred fold improvement in sensitivity. These reactions play a key role in the production of neutrons that drives the slow neutron capture process (s-process) inside of massive stars, which is responsible for the creation of about half of the heavy elements between mass 60 and 90 including copper and silver. Steps for this project include demonstrating optical single atom detection of ytterbium in solid neon, calibrating the efficiency, sensitivity, and selectivity of the technique, and finally building and commissioning a single atom microscope for measuring the nuclear reactions that produce magnesium atoms. Critical steps include a detailed understanding of the optical backgrounds produced by impurities in the various optical components, optical spectroscopy of ytterbium and magnesium in solid noble gases, and the design of a high light collection efficiency diffraction-limited optical imaging system.